rocksdb/db/write_controller_test.cc
sdong 7842920be5 Slow down writes by bytes written
Summary:
We slow down data into the database to the rate of options.delayed_write_rate (a new option) with this patch.

The thread synchronization approach I take is to still synchronize write controller by DB mutex and GetDelay() is inside DB mutex. Try to minimize the frequency of getting time in GetDelay(). I verified it through db_bench and it seems to work

hard_rate_limit is deprecated.

options.delayed_write_rate is still not dynamically changeable. Need to work on it as a follow-up.

Test Plan: Add new unit tests in db_test

Reviewers: yhchiang, rven, kradhakrishnan, anthony, MarkCallaghan, igor

Reviewed By: igor

Subscribers: ikabiljo, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D36351
2015-06-11 20:42:18 -07:00

103 lines
3.4 KiB
C++

// Copyright (c) 2013, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
//
#include "db/write_controller.h"
#include "rocksdb/env.h"
#include "util/testharness.h"
namespace rocksdb {
class WriteControllerTest : public testing::Test {};
class TimeSetEnv : public EnvWrapper {
public:
explicit TimeSetEnv() : EnvWrapper(nullptr) {}
uint64_t now_micros_ = 6666;
virtual uint64_t NowMicros() override { return now_micros_; }
};
TEST_F(WriteControllerTest, SanityTest) {
WriteController controller(10000000u);
auto stop_token_1 = controller.GetStopToken();
auto stop_token_2 = controller.GetStopToken();
ASSERT_TRUE(controller.IsStopped());
stop_token_1.reset();
ASSERT_TRUE(controller.IsStopped());
stop_token_2.reset();
ASSERT_FALSE(controller.IsStopped());
TimeSetEnv env;
auto delay_token_1 = controller.GetDelayToken();
ASSERT_EQ(static_cast<uint64_t>(2000000),
controller.GetDelay(&env, 20000000u));
env.now_micros_ += 1999900u; // sleep debt 1000
auto delay_token_2 = controller.GetDelayToken();
// One refill: 10240 bytes allowed, 1000 used, 9240 left
ASSERT_EQ(static_cast<uint64_t>(1124), controller.GetDelay(&env, 1000u));
env.now_micros_ += 1124u; // sleep debt 0
delay_token_2.reset();
// 1000 used, 8240 left
ASSERT_EQ(static_cast<uint64_t>(0), controller.GetDelay(&env, 1000u));
env.now_micros_ += 100u; // sleep credit 100
// 1000 used, 7240 left
ASSERT_EQ(static_cast<uint64_t>(0), controller.GetDelay(&env, 1000u));
env.now_micros_ += 100u; // sleep credit 200
// One refill: 10240 fileed, sleep credit generates 2000. 8000 used
// 7240 + 10240 + 2000 - 8000 = 11480 left
ASSERT_EQ(static_cast<uint64_t>(1024u), controller.GetDelay(&env, 8000u));
env.now_micros_ += 200u; // sleep debt 824
// 1000 used, 10480 left.
ASSERT_EQ(static_cast<uint64_t>(0), controller.GetDelay(&env, 1000u));
env.now_micros_ += 200u; // sleep debt 624
// Out of bound sleep, still 10480 left
ASSERT_EQ(static_cast<uint64_t>(3000624u),
controller.GetDelay(&env, 30000000u));
env.now_micros_ += 3000724u; // sleep credit 100
// 6000 used, 4480 left.
ASSERT_EQ(static_cast<uint64_t>(0), controller.GetDelay(&env, 6000u));
env.now_micros_ += 200u; // sleep credit 300
// One refill, credit 4480 balance + 3000 credit + 10240 refill
// Use 8000, 9720 left
ASSERT_EQ(static_cast<uint64_t>(1024u), controller.GetDelay(&env, 8000u));
env.now_micros_ += 3024u; // sleep credit 2000
// 1720 left
ASSERT_EQ(static_cast<uint64_t>(0u), controller.GetDelay(&env, 8000u));
// 1720 balance + 20000 credit = 20170 left
// Use 8000, 12170 left
ASSERT_EQ(static_cast<uint64_t>(0u), controller.GetDelay(&env, 8000u));
// 4170 left
ASSERT_EQ(static_cast<uint64_t>(0u), controller.GetDelay(&env, 8000u));
// Need a refill
ASSERT_EQ(static_cast<uint64_t>(1024u), controller.GetDelay(&env, 9000u));
delay_token_1.reset();
ASSERT_EQ(static_cast<uint64_t>(0), controller.GetDelay(&env, 30000000u));
delay_token_1.reset();
ASSERT_FALSE(controller.IsStopped());
}
} // namespace rocksdb
int main(int argc, char** argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}